A known display and keyboard panel for an electronic device such as a handheld or desktop calculator has keyboard and function indicator areas arranged in the vicinity of each other to enable the operator of the device to enter information at the key sections of the keyboard area while viewing the indications appearing in the key sections of the function indication area. This provides ease of use and a minimum chance of error in keying information and thus offers an efficient man-machine interface between the operator and the calculator.
The key sections of the keyboard and function indicator areas are respectively formed by the touch sensor switch areas patterned by discrete segment electrodes provided in a liquid crystal structure which forms part of the display and keyboard panel. In the liquid crystal structure used as the display device, the touch sensor switch areas may be used for the display of images not only on the key sections of the keyboard area but on the key sections of the function indication area. Each of the key sections of the function indication area in a conventional display and keyboard panel of the described type has assigned thereto only one set of information such as, for example, only one mode of operation. This means that there must be provided as many key sections in the function indication area and as many touch sensor switch areas in the liquid crystal structure as the modes of operation available in the electronic device, thus requiring a disproportionately large space for the function indication area and limiting the number of the modes of function which can be displayed.
The liquid crystal device for use in such a display and keyboard panel may be replaced with a device using the matrix-array electrode arrangement in lieu of the segment electrode structure. The use of such a matrix-array liquid crystal device however requires the provision a far larger number of terminals for connection to the drive system for the function indication area than in a display and keyboard panel using the segment electrode liquid crystal structure and accordingly the use of a large-scale integrated circuit of a relatively large capacity for the drive system.
It is, accordingly, an important object of the present invention to provide an improved display and keyboard panel which will provide ease of use and a minimum chance of error in keying information.
It is another important object of the present invention to provide an improved display and keyboard panel which will offer an efficient man-machine interface between the operator and the device.
Yet, it is another important object of the present invention to provide an improved display and keyboard panel which has a minimized space required for the function indication area to allow display of an increased number of modes of function through a liquid crystal device with use of a large-scale integrated circuit of a relatively small capacity for the drive system of the liquid crystal device.